Leonardo da Vinci on knowledge

Iron rusts from disuse; stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind.

Simplicity is the ultimate sophistication.

Anyone who invokes authors in discussion is not using his intelligence but his memory.

One thing only I know, and that is that I know nothing.

Socrates470–399 BC

Information is not knowledge.

There is only one good, knowledge, and one evil, ignorance.

Socrates470–399 BCII: xxxi. Original Greek: ἓν μόνον ἀγαθὸν εἶναι, τὴν ἐπιστήμην, καὶ ἓν μόνον κακόν, τὴν ἀμαθίαν

• Good & Evil